diff options
Diffstat (limited to 'fs/xfs/xfs_buf_item.c')
| -rw-r--r-- | fs/xfs/xfs_buf_item.c | 1090 |
1 files changed, 487 insertions, 603 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index f6a8422e9562..8d85b5eee444 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -1,44 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it would be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_fs.h" +#include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_bit.h" -#include "xfs_sb.h" #include "xfs_mount.h" #include "xfs_trans.h" -#include "xfs_buf_item.h" #include "xfs_trans_priv.h" -#include "xfs_error.h" +#include "xfs_buf_item.h" +#include "xfs_inode.h" +#include "xfs_inode_item.h" +#include "xfs_quota.h" +#include "xfs_dquot_item.h" +#include "xfs_dquot.h" #include "xfs_trace.h" #include "xfs_log.h" +#include "xfs_log_priv.h" +#include "xfs_error.h" -kmem_zone_t *xfs_buf_item_zone; +struct kmem_cache *xfs_buf_item_cache; static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip) { return container_of(lip, struct xfs_buf_log_item, bli_item); } -STATIC void xfs_buf_do_callbacks(struct xfs_buf *bp); +static void +xfs_buf_item_get_format( + struct xfs_buf_log_item *bip, + int count) +{ + ASSERT(bip->bli_formats == NULL); + bip->bli_format_count = count; + + if (count == 1) { + bip->bli_formats = &bip->__bli_format; + return; + } + + bip->bli_formats = kzalloc(count * sizeof(struct xfs_buf_log_format), + GFP_KERNEL | __GFP_NOFAIL); +} + +static void +xfs_buf_item_free_format( + struct xfs_buf_log_item *bip) +{ + if (bip->bli_formats != &bip->__bli_format) { + kfree(bip->bli_formats); + bip->bli_formats = NULL; + } +} + +static void +xfs_buf_item_free( + struct xfs_buf_log_item *bip) +{ + xfs_buf_item_free_format(bip); + kvfree(bip->bli_item.li_lv_shadow); + kmem_cache_free(xfs_buf_item_cache, bip); +} + +/* + * xfs_buf_item_relse() is called when the buf log item is no longer needed. + */ +static void +xfs_buf_item_relse( + struct xfs_buf_log_item *bip) +{ + struct xfs_buf *bp = bip->bli_buf; + + trace_xfs_buf_item_relse(bp, _RET_IP_); + + ASSERT(!test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags)); + ASSERT(atomic_read(&bip->bli_refcount) == 0); + + bp->b_log_item = NULL; + xfs_buf_rele(bp); + xfs_buf_item_free(bip); +} + +/* Is this log iovec plausibly large enough to contain the buffer log format? */ +bool +xfs_buf_log_check_iovec( + struct kvec *iovec) +{ + struct xfs_buf_log_format *blfp = iovec->iov_base; + char *bmp_end; + char *item_end; + + if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->iov_len) + return false; + + item_end = (char *)iovec->iov_base + iovec->iov_len; + bmp_end = (char *)&blfp->blf_data_map[blfp->blf_map_size]; + return bmp_end <= item_end; +} static inline int xfs_buf_log_format_size( @@ -49,76 +113,75 @@ xfs_buf_log_format_size( } /* - * This returns the number of log iovecs needed to log the - * given buf log item. - * - * It calculates this as 1 iovec for the buf log format structure - * and 1 for each stretch of non-contiguous chunks to be logged. - * Contiguous chunks are logged in a single iovec. + * Return the number of log iovecs and space needed to log the given buf log + * item segment. * - * If the XFS_BLI_STALE flag has been set, then log nothing. + * It calculates this as 1 iovec for the buf log format structure and 1 for each + * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged + * in a single iovec. */ STATIC void xfs_buf_item_size_segment( - struct xfs_buf_log_item *bip, - struct xfs_buf_log_format *blfp, - int *nvecs, - int *nbytes) + struct xfs_buf_log_item *bip, + struct xfs_buf_log_format *blfp, + uint offset, + int *nvecs, + int *nbytes) { - struct xfs_buf *bp = bip->bli_buf; - int next_bit; - int last_bit; + int first_bit; + int nbits; - last_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0); - if (last_bit == -1) + first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0); + if (first_bit == -1) return; - /* - * initial count for a dirty buffer is 2 vectors - the format structure - * and the first dirty region. - */ - *nvecs += 2; - *nbytes += xfs_buf_log_format_size(blfp) + XFS_BLF_CHUNK; + (*nvecs)++; + *nbytes += xfs_buf_log_format_size(blfp); + + do { + nbits = xfs_contig_bits(blfp->blf_data_map, + blfp->blf_map_size, first_bit); + ASSERT(nbits > 0); + (*nvecs)++; + *nbytes += nbits * XFS_BLF_CHUNK; - while (last_bit != -1) { /* * This takes the bit number to start looking from and * returns the next set bit from there. It returns -1 * if there are no more bits set or the start bit is * beyond the end of the bitmap. */ - next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, - last_bit + 1); - /* - * If we run out of bits, leave the loop, - * else if we find a new set of bits bump the number of vecs, - * else keep scanning the current set of bits. - */ - if (next_bit == -1) { - break; - } else if (next_bit != last_bit + 1) { - last_bit = next_bit; - (*nvecs)++; - } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) != - (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) + - XFS_BLF_CHUNK)) { - last_bit = next_bit; - (*nvecs)++; - } else { - last_bit++; - } - *nbytes += XFS_BLF_CHUNK; - } + first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, + (uint)first_bit + nbits + 1); + } while (first_bit != -1); + + return; } /* - * This returns the number of log iovecs needed to log the given buf log item. - * - * It calculates this as 1 iovec for the buf log format structure and 1 for each - * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged - * in a single iovec. + * Compute the worst case log item overhead for an invalidated buffer with the + * given map count and block size. + */ +unsigned int +xfs_buf_inval_log_space( + unsigned int map_count, + unsigned int blocksize) +{ + unsigned int chunks = DIV_ROUND_UP(blocksize, XFS_BLF_CHUNK); + unsigned int bitmap_size = DIV_ROUND_UP(chunks, NBWORD); + unsigned int ret = + offsetof(struct xfs_buf_log_format, blf_data_map) + + (bitmap_size * sizeof_field(struct xfs_buf_log_format, + blf_data_map[0])); + + return ret * map_count; +} + +/* + * Return the number of log iovecs and space needed to log the given buf log + * item. * - * Discontiguous buffers need a format structure per region that that is being + * Discontiguous buffers need a format structure per region that is being * logged. This makes the changes in the buffer appear to log recovery as though * they came from separate buffers, just like would occur if multiple buffers * were used instead of a single discontiguous buffer. This enables @@ -126,7 +189,11 @@ xfs_buf_item_size_segment( * what ends up on disk. * * If the XFS_BLI_STALE flag has been set, then log nothing but the buf log - * format structures. + * format structures. If the item has previously been logged and has dirty + * regions, we do not relog them in stale buffers. This has the effect of + * reducing the size of the relogged item by the amount of dirty data tracked + * by the log item. This can result in the committing transaction reducing the + * amount of space being consumed by the CIL. */ STATIC void xfs_buf_item_size( @@ -135,14 +202,17 @@ xfs_buf_item_size( int *nbytes) { struct xfs_buf_log_item *bip = BUF_ITEM(lip); + struct xfs_buf *bp = bip->bli_buf; int i; + int bytes; + uint offset = 0; ASSERT(atomic_read(&bip->bli_refcount) > 0); if (bip->bli_flags & XFS_BLI_STALE) { /* - * The buffer is stale, so all we need to log - * is the buf log format structure with the - * cancel flag in it. + * The buffer is stale, so all we need to log is the buf log + * format structure with the cancel flag in it as we are never + * going to replay the changes tracked in the log item. */ trace_xfs_buf_item_size_stale(bip); ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL); @@ -157,9 +227,9 @@ xfs_buf_item_size( if (bip->bli_flags & XFS_BLI_ORDERED) { /* - * The buffer has been logged just to order it. - * It is not being included in the transaction - * commit, so no vectors are used at all. + * The buffer has been logged just to order it. It is not being + * included in the transaction commit, so no vectors are used at + * all. */ trace_xfs_buf_item_size_ordered(bip); *nvecs = XFS_LOG_VEC_ORDERED; @@ -167,7 +237,7 @@ xfs_buf_item_size( } /* - * the vector count is based on the number of buffer vectors we have + * The vector count is based on the number of buffer vectors we have * dirty bits in. This will only be greater than one when we have a * compound buffer with more than one segment dirty. Hence for compound * buffers we need to track which segment the dirty bits correspond to, @@ -175,10 +245,19 @@ xfs_buf_item_size( * count for the extra buf log format structure that will need to be * written. */ + bytes = 0; for (i = 0; i < bip->bli_format_count; i++) { - xfs_buf_item_size_segment(bip, &bip->bli_formats[i], - nvecs, nbytes); + xfs_buf_item_size_segment(bip, &bip->bli_formats[i], offset, + nvecs, &bytes); + offset += BBTOB(bp->b_maps[i].bm_len); } + + /* + * Round up the buffer size required to minimise the number of memory + * allocations that need to be done as this item grows when relogged by + * repeated modifications. + */ + *nbytes = round_up(bytes, 512); trace_xfs_buf_item_size(bip); } @@ -197,18 +276,6 @@ xfs_buf_item_copy_iovec( nbits * XFS_BLF_CHUNK); } -static inline bool -xfs_buf_item_straddle( - struct xfs_buf *bp, - uint offset, - int next_bit, - int last_bit) -{ - return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) != - (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) + - XFS_BLF_CHUNK); -} - static void xfs_buf_item_format_segment( struct xfs_buf_log_item *bip, @@ -217,12 +284,10 @@ xfs_buf_item_format_segment( uint offset, struct xfs_buf_log_format *blfp) { - struct xfs_buf *bp = bip->bli_buf; - uint base_size; - int first_bit; - int last_bit; - int next_bit; - uint nbits; + struct xfs_buf *bp = bip->bli_buf; + uint base_size; + int first_bit; + uint nbits; /* copy the flags across from the base format item */ blfp->blf_flags = bip->__bli_format.blf_flags; @@ -261,42 +326,26 @@ xfs_buf_item_format_segment( /* * Fill in an iovec for each set of contiguous chunks. */ - last_bit = first_bit; - nbits = 1; - for (;;) { + do { + ASSERT(first_bit >= 0); + nbits = xfs_contig_bits(blfp->blf_data_map, + blfp->blf_map_size, first_bit); + ASSERT(nbits > 0); + xfs_buf_item_copy_iovec(lv, vecp, bp, offset, + first_bit, nbits); + blfp->blf_size++; + /* * This takes the bit number to start looking from and * returns the next set bit from there. It returns -1 * if there are no more bits set or the start bit is * beyond the end of the bitmap. */ - next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, - (uint)last_bit + 1); - /* - * If we run out of bits fill in the last iovec and get out of - * the loop. Else if we start a new set of bits then fill in - * the iovec for the series we were looking at and start - * counting the bits in the new one. Else we're still in the - * same set of bits so just keep counting and scanning. - */ - if (next_bit == -1) { - xfs_buf_item_copy_iovec(lv, vecp, bp, offset, - first_bit, nbits); - blfp->blf_size++; - break; - } else if (next_bit != last_bit + 1 || - xfs_buf_item_straddle(bp, offset, next_bit, last_bit)) { - xfs_buf_item_copy_iovec(lv, vecp, bp, offset, - first_bit, nbits); - blfp->blf_size++; - first_bit = next_bit; - last_bit = next_bit; - nbits = 1; - } else { - last_bit++; - nbits++; - } - } + first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, + (uint)first_bit + nbits + 1); + } while (first_bit != -1); + + return; } /* @@ -322,6 +371,8 @@ xfs_buf_item_format( ASSERT((bip->bli_flags & XFS_BLI_STALE) || (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF)); + ASSERT(!(bip->bli_flags & XFS_BLI_ORDERED) || + (bip->bli_flags & XFS_BLI_STALE)); /* @@ -339,23 +390,13 @@ xfs_buf_item_format( * occurs during recovery. */ if (bip->bli_flags & XFS_BLI_INODE_BUF) { - if (xfs_sb_version_hascrc(&lip->li_mountp->m_sb) || + if (xfs_has_v3inodes(lip->li_log->l_mp) || !((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && xfs_log_item_in_current_chkpt(lip))) bip->__bli_format.blf_flags |= XFS_BLF_INODE_BUF; bip->bli_flags &= ~XFS_BLI_INODE_BUF; } - if ((bip->bli_flags & (XFS_BLI_ORDERED|XFS_BLI_STALE)) == - XFS_BLI_ORDERED) { - /* - * The buffer has been logged just to order it. It is not being - * included in the transaction commit, so don't format it. - */ - trace_xfs_buf_item_format_ordered(bip); - return; - } - for (i = 0; i < bip->bli_format_count; i++) { xfs_buf_item_format_segment(bip, lv, &vecp, offset, &bip->bli_formats[i]); @@ -372,10 +413,18 @@ xfs_buf_item_format( * This is called to pin the buffer associated with the buf log item in memory * so it cannot be written out. * - * We also always take a reference to the buffer log item here so that the bli - * is held while the item is pinned in memory. This means that we can - * unconditionally drop the reference count a transaction holds when the - * transaction is completed. + * We take a reference to the buffer log item here so that the BLI life cycle + * extends at least until the buffer is unpinned via xfs_buf_item_unpin() and + * inserted into the AIL. + * + * We also need to take a reference to the buffer itself as the BLI unpin + * processing requires accessing the buffer after the BLI has dropped the final + * BLI reference. See xfs_buf_item_unpin() for an explanation. + * If unpins race to drop the final BLI reference and only the + * BLI owns a reference to the buffer, then the loser of the race can have the + * buffer fgreed from under it (e.g. on shutdown). Taking a buffer reference per + * pin count ensures the life cycle of the buffer extends for as + * long as we hold the buffer pin reference in xfs_buf_item_unpin(). */ STATIC void xfs_buf_item_pin( @@ -390,22 +439,66 @@ xfs_buf_item_pin( trace_xfs_buf_item_pin(bip); + xfs_buf_hold(bip->bli_buf); atomic_inc(&bip->bli_refcount); atomic_inc(&bip->bli_buf->b_pin_count); } /* - * This is called to unpin the buffer associated with the buf log - * item which was previously pinned with a call to xfs_buf_item_pin(). + * For a stale BLI, process all the necessary completions that must be + * performed when the final BLI reference goes away. The buffer will be + * referenced and locked here - we return to the caller with the buffer still + * referenced and locked for them to finalise processing of the buffer. + */ +static void +xfs_buf_item_finish_stale( + struct xfs_buf_log_item *bip) +{ + struct xfs_buf *bp = bip->bli_buf; + struct xfs_log_item *lip = &bip->bli_item; + + ASSERT(bip->bli_flags & XFS_BLI_STALE); + ASSERT(xfs_buf_islocked(bp)); + ASSERT(bp->b_flags & XBF_STALE); + ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL); + ASSERT(list_empty(&lip->li_trans)); + ASSERT(!bp->b_transp); + + if (bip->bli_flags & XFS_BLI_STALE_INODE) { + xfs_buf_item_done(bp); + xfs_buf_inode_iodone(bp); + ASSERT(list_empty(&bp->b_li_list)); + return; + } + + /* + * We may or may not be on the AIL here, xfs_trans_ail_delete() will do + * the right thing regardless of the situation in which we are called. + */ + xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR); + xfs_buf_item_relse(bip); + ASSERT(bp->b_log_item == NULL); +} + +/* + * This is called to unpin the buffer associated with the buf log item which was + * previously pinned with a call to xfs_buf_item_pin(). We enter this function + * with a buffer pin count, a buffer reference and a BLI reference. * - * Also drop the reference to the buf item for the current transaction. - * If the XFS_BLI_STALE flag is set and we are the last reference, - * then free up the buf log item and unlock the buffer. + * We must drop the BLI reference before we unpin the buffer because the AIL + * doesn't acquire a BLI reference whenever it accesses it. Therefore if the + * refcount drops to zero, the bli could still be AIL resident and the buffer + * submitted for I/O at any point before we return. This can result in IO + * completion freeing the buffer while we are still trying to access it here. + * This race condition can also occur in shutdown situations where we abort and + * unpin buffers from contexts other that journal IO completion. * - * If the remove flag is set we are called from uncommit in the - * forced-shutdown path. If that is true and the reference count on - * the log item is going to drop to zero we need to free the item's - * descriptor in the transaction. + * Hence we have to hold a buffer reference per pin count to ensure that the + * buffer cannot be freed until we have finished processing the unpin operation. + * The reference is taken in xfs_buf_item_pin(), and we must hold it until we + * are done processing the buffer state. In the case of an abort (remove = + * true) then we re-use the current pin reference as the IO reference we hand + * off to IO failure handling. */ STATIC void xfs_buf_item_unpin( @@ -413,99 +506,66 @@ xfs_buf_item_unpin( int remove) { struct xfs_buf_log_item *bip = BUF_ITEM(lip); - xfs_buf_t *bp = bip->bli_buf; - struct xfs_ail *ailp = lip->li_ailp; - int stale = bip->bli_flags & XFS_BLI_STALE; - int freed; + struct xfs_buf *bp = bip->bli_buf; + int stale = bip->bli_flags & XFS_BLI_STALE; + int freed; - ASSERT(bp->b_fspriv == bip); + ASSERT(bp->b_log_item == bip); ASSERT(atomic_read(&bip->bli_refcount) > 0); trace_xfs_buf_item_unpin(bip); freed = atomic_dec_and_test(&bip->bli_refcount); - if (atomic_dec_and_test(&bp->b_pin_count)) wake_up_all(&bp->b_waiters); - if (freed && stale) { - ASSERT(bip->bli_flags & XFS_BLI_STALE); - ASSERT(xfs_buf_islocked(bp)); - ASSERT(bp->b_flags & XBF_STALE); - ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL); + /* + * Nothing to do but drop the buffer pin reference if the BLI is + * still active. + */ + if (!freed) { + xfs_buf_rele(bp); + return; + } + if (stale) { trace_xfs_buf_item_unpin_stale(bip); - if (remove) { - /* - * If we are in a transaction context, we have to - * remove the log item from the transaction as we are - * about to release our reference to the buffer. If we - * don't, the unlock that occurs later in - * xfs_trans_uncommit() will try to reference the - * buffer which we no longer have a hold on. - */ - if (lip->li_desc) - xfs_trans_del_item(lip); - - /* - * Since the transaction no longer refers to the buffer, - * the buffer should no longer refer to the transaction. - */ - bp->b_transp = NULL; - } - /* - * If we get called here because of an IO error, we may - * or may not have the item on the AIL. xfs_trans_ail_delete() - * will take care of that situation. - * xfs_trans_ail_delete() drops the AIL lock. + * The buffer has been locked and referenced since it was marked + * stale so we own both lock and reference exclusively here. We + * do not need the pin reference any more, so drop it now so + * that we only have one reference to drop once item completion + * processing is complete. */ - if (bip->bli_flags & XFS_BLI_STALE_INODE) { - xfs_buf_do_callbacks(bp); - bp->b_fspriv = NULL; - bp->b_iodone = NULL; - } else { - spin_lock(&ailp->xa_lock); - xfs_trans_ail_delete(ailp, lip, SHUTDOWN_LOG_IO_ERROR); - xfs_buf_item_relse(bp); - ASSERT(bp->b_fspriv == NULL); - } + xfs_buf_rele(bp); + xfs_buf_item_finish_stale(bip); xfs_buf_relse(bp); - } else if (freed && remove) { + return; + } + + if (remove) { /* - * There are currently two references to the buffer - the active - * LRU reference and the buf log item. What we are about to do - * here - simulate a failed IO completion - requires 3 - * references. - * - * The LRU reference is removed by the xfs_buf_stale() call. The - * buf item reference is removed by the xfs_buf_iodone() - * callback that is run by xfs_buf_do_callbacks() during ioend - * processing (via the bp->b_iodone callback), and then finally - * the ioend processing will drop the IO reference if the buffer - * is marked XBF_ASYNC. - * - * Hence we need to take an additional reference here so that IO - * completion processing doesn't free the buffer prematurely. + * We need to simulate an async IO failures here to ensure that + * the correct error completion is run on this buffer. This + * requires a reference to the buffer and for the buffer to be + * locked. We can safely pass ownership of the pin reference to + * the IO to ensure that nothing can free the buffer while we + * wait for the lock and then run the IO failure completion. */ xfs_buf_lock(bp); - xfs_buf_hold(bp); bp->b_flags |= XBF_ASYNC; - xfs_buf_ioerror(bp, -EIO); - bp->b_flags &= ~XBF_DONE; - xfs_buf_stale(bp); - xfs_buf_ioend(bp); + xfs_buf_ioend_fail(bp); + return; } -} -/* - * Buffer IO error rate limiting. Limit it to no more than 10 messages per 30 - * seconds so as to not spam logs too much on repeated detection of the same - * buffer being bad.. - */ - -static DEFINE_RATELIMIT_STATE(xfs_buf_write_fail_rl_state, 30 * HZ, 10); + /* + * BLI has no more active references - it will be moved to the AIL to + * manage the remaining BLI/buffer life cycle. There is nothing left for + * us to do here so drop the pin reference to the buffer. + */ + xfs_buf_rele(bp); +} STATIC uint xfs_buf_item_push( @@ -536,11 +596,10 @@ xfs_buf_item_push( trace_xfs_buf_item_push(bip); /* has a previous flush failed due to IO errors? */ - if ((bp->b_flags & XBF_WRITE_FAIL) && - ___ratelimit(&xfs_buf_write_fail_rl_state, "XFS: Failing async write")) { - xfs_warn(bp->b_target->bt_mount, -"Failing async write on buffer block 0x%llx. Retrying async write.", - (long long)bp->b_bn); + if (bp->b_flags & XBF_WRITE_FAIL) { + xfs_buf_alert_ratelimited(bp, "XFS: Failing async write", + "Failing async write on buffer block 0x%llx. Retrying async write.", + (long long)xfs_buf_daddr(bp)); } if (!xfs_buf_delwri_queue(bp, buffer_list)) @@ -550,6 +609,48 @@ xfs_buf_item_push( } /* + * Drop the buffer log item refcount and take appropriate action. This helper + * determines whether the bli must be freed or not, since a decrement to zero + * does not necessarily mean the bli is unused. + */ +void +xfs_buf_item_put( + struct xfs_buf_log_item *bip) +{ + + ASSERT(xfs_buf_islocked(bip->bli_buf)); + + /* drop the bli ref and return if it wasn't the last one */ + if (!atomic_dec_and_test(&bip->bli_refcount)) + return; + + /* If the BLI is in the AIL, then it is still dirty and in use */ + if (test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags)) { + ASSERT(bip->bli_flags & XFS_BLI_DIRTY); + return; + } + + /* + * In shutdown conditions, we can be asked to free a dirty BLI that + * isn't in the AIL. This can occur due to a checkpoint aborting a BLI + * instead of inserting it into the AIL at checkpoint IO completion. If + * there's another bli reference (e.g. a btree cursor holds a clean + * reference) and it is released via xfs_trans_brelse(), we can get here + * with that aborted, dirty BLI. In this case, it is safe to free the + * dirty BLI immediately, as it is not in the AIL and there are no + * other references to it. + * + * We should never get here with a stale BLI via that path as + * xfs_trans_brelse() specifically holds onto stale buffers rather than + * releasing them. + */ + ASSERT(!(bip->bli_flags & XFS_BLI_DIRTY) || + test_bit(XFS_LI_ABORTED, &bip->bli_item.li_flags)); + ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); + xfs_buf_item_relse(bip); +} + +/* * Release the buffer associated with the buf log item. If there is no dirty * logged data associated with the buffer recorded in the buf log item, then * free the buf log item and remove the reference to it in the buffer. @@ -567,96 +668,109 @@ xfs_buf_item_push( * if necessary but do not unlock the buffer. This is for support of * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't * free the item. + * + * If the XFS_BLI_STALE flag is set, the last reference to the BLI *must* + * perform a completion abort of any objects attached to the buffer for IO + * tracking purposes. This generally only happens in shutdown situations, + * normally xfs_buf_item_unpin() will drop the last BLI reference and perform + * completion processing. However, because transaction completion can race with + * checkpoint completion during a shutdown, this release context may end up + * being the last active reference to the BLI and so needs to perform this + * cleanup. */ STATIC void -xfs_buf_item_unlock( +xfs_buf_item_release( struct xfs_log_item *lip) { struct xfs_buf_log_item *bip = BUF_ITEM(lip); struct xfs_buf *bp = bip->bli_buf; - bool clean; - bool aborted; - int flags; + bool hold = bip->bli_flags & XFS_BLI_HOLD; + bool stale = bip->bli_flags & XFS_BLI_STALE; + bool aborted = test_bit(XFS_LI_ABORTED, + &lip->li_flags); + bool dirty = bip->bli_flags & XFS_BLI_DIRTY; +#if defined(DEBUG) || defined(XFS_WARN) + bool ordered = bip->bli_flags & XFS_BLI_ORDERED; +#endif - /* Clear the buffer's association with this transaction. */ - bp->b_transp = NULL; + trace_xfs_buf_item_release(bip); + + ASSERT(xfs_buf_islocked(bp)); /* - * If this is a transaction abort, don't return early. Instead, allow - * the brelse to happen. Normally it would be done for stale - * (cancelled) buffers at unpin time, but we'll never go through the - * pin/unpin cycle if we abort inside commit. + * The bli dirty state should match whether the blf has logged segments + * except for ordered buffers, where only the bli should be dirty. */ - aborted = (lip->li_flags & XFS_LI_ABORTED) ? true : false; + ASSERT((!ordered && dirty == xfs_buf_item_dirty_format(bip)) || + (ordered && dirty && !xfs_buf_item_dirty_format(bip))); + ASSERT(!stale || (bip->__bli_format.blf_flags & XFS_BLF_CANCEL)); + /* - * Before possibly freeing the buf item, copy the per-transaction state - * so we can reference it safely later after clearing it from the - * buffer log item. + * Clear the buffer's association with this transaction and + * per-transaction state from the bli, which has been copied above. */ - flags = bip->bli_flags; + bp->b_transp = NULL; bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED); + /* If there are other references, then we have nothing to do. */ + if (!atomic_dec_and_test(&bip->bli_refcount)) + goto out_release; + /* - * If the buf item is marked stale, then don't do anything. We'll - * unlock the buffer and free the buf item when the buffer is unpinned - * for the last time. + * Stale buffer completion frees the BLI, unlocks and releases the + * buffer. Neither the BLI or buffer are safe to reference after this + * call, so there's nothing more we need to do here. + * + * If we get here with a stale buffer and references to the BLI remain, + * we must not unlock the buffer as the last BLI reference owns lock + * context, not us. */ - if (flags & XFS_BLI_STALE) { - trace_xfs_buf_item_unlock_stale(bip); - ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL); - if (!aborted) { - atomic_dec(&bip->bli_refcount); - return; - } + if (stale) { + xfs_buf_item_finish_stale(bip); + xfs_buf_relse(bp); + ASSERT(!hold); + return; } - trace_xfs_buf_item_unlock(bip); - /* - * If the buf item isn't tracking any data, free it, otherwise drop the - * reference we hold to it. If we are aborting the transaction, this may - * be the only reference to the buf item, so we free it anyway - * regardless of whether it is dirty or not. A dirty abort implies a - * shutdown, anyway. - * - * Ordered buffers are dirty but may have no recorded changes, so ensure - * we only release clean items here. + * Dirty or clean, aborted items are done and need to be removed from + * the AIL and released. This frees the BLI, but leaves the buffer + * locked and referenced. */ - clean = (flags & XFS_BLI_DIRTY) ? false : true; - if (clean) { - int i; - for (i = 0; i < bip->bli_format_count; i++) { - if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map, - bip->bli_formats[i].blf_map_size)) { - clean = false; - break; - } - } + if (aborted || xlog_is_shutdown(lip->li_log)) { + ASSERT(list_empty(&bip->bli_buf->b_li_list)); + xfs_buf_item_done(bp); + goto out_release; } /* - * Clean buffers, by definition, cannot be in the AIL. However, aborted - * buffers may be in the AIL regardless of dirty state. An aborted - * transaction that invalidates a buffer already in the AIL may have - * marked it stale and cleared the dirty state, for example. + * Clean, unreferenced BLIs can be immediately freed, leaving the buffer + * locked and referenced. * - * Therefore if we are aborting a buffer and we've just taken the last - * reference away, we have to check if it is in the AIL before freeing - * it. We need to free it in this case, because an aborted transaction - * has already shut the filesystem down and this is the last chance we - * will have to do so. + * Dirty, unreferenced BLIs *must* be in the AIL awaiting writeback. */ - if (atomic_dec_and_test(&bip->bli_refcount)) { - if (aborted) { - ASSERT(XFS_FORCED_SHUTDOWN(lip->li_mountp)); - xfs_trans_ail_remove(lip, SHUTDOWN_LOG_IO_ERROR); - xfs_buf_item_relse(bp); - } else if (clean) - xfs_buf_item_relse(bp); - } + if (!dirty) + xfs_buf_item_relse(bip); + else + ASSERT(test_bit(XFS_LI_IN_AIL, &lip->li_flags)); - if (!(flags & XFS_BLI_HOLD)) - xfs_buf_relse(bp); + /* Not safe to reference the BLI from here */ +out_release: + /* + * If we get here with a stale buffer, we must not unlock the + * buffer as the last BLI reference owns lock context, not us. + */ + if (stale || hold) + return; + xfs_buf_relse(bp); +} + +STATIC void +xfs_buf_item_committing( + struct xfs_log_item *lip, + xfs_csn_t seq) +{ + return xfs_buf_item_release(lip); } /* @@ -691,87 +805,77 @@ xfs_buf_item_committed( return lsn; } -STATIC void -xfs_buf_item_committing( - struct xfs_log_item *lip, - xfs_lsn_t commit_lsn) +#ifdef DEBUG_EXPENSIVE +static int +xfs_buf_item_precommit( + struct xfs_trans *tp, + struct xfs_log_item *lip) { + struct xfs_buf_log_item *bip = BUF_ITEM(lip); + struct xfs_buf *bp = bip->bli_buf; + struct xfs_mount *mp = bp->b_mount; + xfs_failaddr_t fa; + + if (!bp->b_ops || !bp->b_ops->verify_struct) + return 0; + if (bip->bli_flags & XFS_BLI_STALE) + return 0; + + fa = bp->b_ops->verify_struct(bp); + if (fa) { + xfs_buf_verifier_error(bp, -EFSCORRUPTED, bp->b_ops->name, + bp->b_addr, BBTOB(bp->b_length), fa); + xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); + ASSERT(fa == NULL); + } + + return 0; } +#else +# define xfs_buf_item_precommit NULL +#endif -/* - * This is the ops vector shared by all buf log items. - */ static const struct xfs_item_ops xfs_buf_item_ops = { .iop_size = xfs_buf_item_size, + .iop_precommit = xfs_buf_item_precommit, .iop_format = xfs_buf_item_format, .iop_pin = xfs_buf_item_pin, .iop_unpin = xfs_buf_item_unpin, - .iop_unlock = xfs_buf_item_unlock, + .iop_release = xfs_buf_item_release, + .iop_committing = xfs_buf_item_committing, .iop_committed = xfs_buf_item_committed, .iop_push = xfs_buf_item_push, - .iop_committing = xfs_buf_item_committing }; -STATIC int -xfs_buf_item_get_format( - struct xfs_buf_log_item *bip, - int count) -{ - ASSERT(bip->bli_formats == NULL); - bip->bli_format_count = count; - - if (count == 1) { - bip->bli_formats = &bip->__bli_format; - return 0; - } - - bip->bli_formats = kmem_zalloc(count * sizeof(struct xfs_buf_log_format), - KM_SLEEP); - if (!bip->bli_formats) - return -ENOMEM; - return 0; -} - -STATIC void -xfs_buf_item_free_format( - struct xfs_buf_log_item *bip) -{ - if (bip->bli_formats != &bip->__bli_format) { - kmem_free(bip->bli_formats); - bip->bli_formats = NULL; - } -} - /* * Allocate a new buf log item to go with the given buffer. - * Set the buffer's b_fsprivate field to point to the new - * buf log item. If there are other item's attached to the - * buffer (see xfs_buf_attach_iodone() below), then put the - * buf log item at the front. + * Set the buffer's b_log_item field to point to the new + * buf log item. */ int xfs_buf_item_init( struct xfs_buf *bp, struct xfs_mount *mp) { - struct xfs_log_item *lip = bp->b_fspriv; - struct xfs_buf_log_item *bip; + struct xfs_buf_log_item *bip = bp->b_log_item; int chunks; int map_size; - int error; int i; /* * Check to see if there is already a buf log item for - * this buffer. If there is, it is guaranteed to be - * the first. If we do already have one, there is + * this buffer. If we do already have one, there is * nothing to do here so return. */ - ASSERT(bp->b_target->bt_mount == mp); - if (lip != NULL && lip->li_type == XFS_LI_BUF) + ASSERT(bp->b_mount == mp); + if (bip) { + ASSERT(bip->bli_item.li_type == XFS_LI_BUF); + ASSERT(!bp->b_transp); + ASSERT(bip->bli_buf == bp); return 0; + } - bip = kmem_zone_zalloc(xfs_buf_item_zone, KM_SLEEP); + bip = kmem_cache_zalloc(xfs_buf_item_cache, GFP_KERNEL | __GFP_NOFAIL); xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops); bip->bli_buf = bp; @@ -784,32 +888,29 @@ xfs_buf_item_init( * Discontiguous buffer support follows the layout of the underlying * buffer. This makes the implementation as simple as possible. */ - error = xfs_buf_item_get_format(bip, bp->b_map_count); - ASSERT(error == 0); - if (error) { /* to stop gcc throwing set-but-unused warnings */ - kmem_zone_free(xfs_buf_item_zone, bip); - return error; - } - + xfs_buf_item_get_format(bip, bp->b_map_count); for (i = 0; i < bip->bli_format_count; i++) { chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len), XFS_BLF_CHUNK); map_size = DIV_ROUND_UP(chunks, NBWORD); + if (map_size > XFS_BLF_DATAMAP_SIZE) { + kmem_cache_free(xfs_buf_item_cache, bip); + xfs_err(mp, + "buffer item dirty bitmap (%u uints) too small to reflect %u bytes!", + map_size, + BBTOB(bp->b_maps[i].bm_len)); + return -EFSCORRUPTED; + } + bip->bli_formats[i].blf_type = XFS_LI_BUF; bip->bli_formats[i].blf_blkno = bp->b_maps[i].bm_bn; bip->bli_formats[i].blf_len = bp->b_maps[i].bm_len; bip->bli_formats[i].blf_map_size = map_size; } - /* - * Put the buf item into the list of items attached to the - * buffer at the front. - */ - if (bp->b_fspriv) - bip->bli_item.li_bio_list = bp->b_fspriv; - bp->b_fspriv = bip; + bp->b_log_item = bip; xfs_buf_hold(bp); return 0; } @@ -835,6 +936,9 @@ xfs_buf_item_log_segment( uint end_bit; uint mask; + ASSERT(first < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD); + ASSERT(last < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD); + /* * Convert byte offsets to bit numbers. */ @@ -867,7 +971,7 @@ xfs_buf_item_log_segment( * of the last bit to be set in this word plus one. */ if (bit) { - end_bit = MIN(bit + bits_to_set, (uint)NBWORD); + end_bit = min(bit + bits_to_set, (uint)NBWORD); mask = ((1U << (end_bit - bit)) - 1) << bit; *wordp |= mask; wordp++; @@ -881,7 +985,7 @@ xfs_buf_item_log_segment( * first_bit and last_bit. */ while ((bits_to_set - bits_set) >= NBWORD) { - *wordp |= 0xffffffff; + *wordp = 0xffffffff; bits_set += NBWORD; wordp++; } @@ -902,7 +1006,7 @@ xfs_buf_item_log_segment( */ void xfs_buf_item_log( - xfs_buf_log_item_t *bip, + struct xfs_buf_log_item *bip, uint first, uint last) { @@ -945,262 +1049,42 @@ xfs_buf_item_log( /* - * Return 1 if the buffer has been logged or ordered in a transaction (at any - * point, not just the current transaction) and 0 if not. + * Return true if the buffer has any ranges logged/dirtied by a transaction, + * false otherwise. */ -uint -xfs_buf_item_dirty( - xfs_buf_log_item_t *bip) -{ - return (bip->bli_flags & XFS_BLI_DIRTY); -} - -STATIC void -xfs_buf_item_free( - xfs_buf_log_item_t *bip) -{ - xfs_buf_item_free_format(bip); - kmem_free(bip->bli_item.li_lv_shadow); - kmem_zone_free(xfs_buf_item_zone, bip); -} - -/* - * This is called when the buf log item is no longer needed. It should - * free the buf log item associated with the given buffer and clear - * the buffer's pointer to the buf log item. If there are no more - * items in the list, clear the b_iodone field of the buffer (see - * xfs_buf_attach_iodone() below). - */ -void -xfs_buf_item_relse( - xfs_buf_t *bp) -{ - xfs_buf_log_item_t *bip = bp->b_fspriv; - - trace_xfs_buf_item_relse(bp, _RET_IP_); - ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL)); - - bp->b_fspriv = bip->bli_item.li_bio_list; - if (bp->b_fspriv == NULL) - bp->b_iodone = NULL; - - xfs_buf_rele(bp); - xfs_buf_item_free(bip); -} - - -/* - * Add the given log item with its callback to the list of callbacks - * to be called when the buffer's I/O completes. If it is not set - * already, set the buffer's b_iodone() routine to be - * xfs_buf_iodone_callbacks() and link the log item into the list of - * items rooted at b_fsprivate. Items are always added as the second - * entry in the list if there is a first, because the buf item code - * assumes that the buf log item is first. - */ -void -xfs_buf_attach_iodone( - xfs_buf_t *bp, - void (*cb)(xfs_buf_t *, xfs_log_item_t *), - xfs_log_item_t *lip) -{ - xfs_log_item_t *head_lip; - - ASSERT(xfs_buf_islocked(bp)); - - lip->li_cb = cb; - head_lip = bp->b_fspriv; - if (head_lip) { - lip->li_bio_list = head_lip->li_bio_list; - head_lip->li_bio_list = lip; - } else { - bp->b_fspriv = lip; - } - - ASSERT(bp->b_iodone == NULL || - bp->b_iodone == xfs_buf_iodone_callbacks); - bp->b_iodone = xfs_buf_iodone_callbacks; -} - -/* - * We can have many callbacks on a buffer. Running the callbacks individually - * can cause a lot of contention on the AIL lock, so we allow for a single - * callback to be able to scan the remaining lip->li_bio_list for other items - * of the same type and callback to be processed in the first call. - * - * As a result, the loop walking the callback list below will also modify the - * list. it removes the first item from the list and then runs the callback. - * The loop then restarts from the new head of the list. This allows the - * callback to scan and modify the list attached to the buffer and we don't - * have to care about maintaining a next item pointer. - */ -STATIC void -xfs_buf_do_callbacks( - struct xfs_buf *bp) -{ - struct xfs_log_item *lip; - - while ((lip = bp->b_fspriv) != NULL) { - bp->b_fspriv = lip->li_bio_list; - ASSERT(lip->li_cb != NULL); - /* - * Clear the next pointer so we don't have any - * confusion if the item is added to another buf. - * Don't touch the log item after calling its - * callback, because it could have freed itself. - */ - lip->li_bio_list = NULL; - lip->li_cb(bp, lip); - } -} - -static bool -xfs_buf_iodone_callback_error( - struct xfs_buf *bp) +bool +xfs_buf_item_dirty_format( + struct xfs_buf_log_item *bip) { - struct xfs_log_item *lip = bp->b_fspriv; - struct xfs_mount *mp = lip->li_mountp; - static ulong lasttime; - static xfs_buftarg_t *lasttarg; - struct xfs_error_cfg *cfg; - - /* - * If we've already decided to shutdown the filesystem because of - * I/O errors, there's no point in giving this a retry. - */ - if (XFS_FORCED_SHUTDOWN(mp)) - goto out_stale; - - if (bp->b_target != lasttarg || - time_after(jiffies, (lasttime + 5*HZ))) { - lasttime = jiffies; - xfs_buf_ioerror_alert(bp, __func__); - } - lasttarg = bp->b_target; - - /* synchronous writes will have callers process the error */ - if (!(bp->b_flags & XBF_ASYNC)) - goto out_stale; - - trace_xfs_buf_item_iodone_async(bp, _RET_IP_); - ASSERT(bp->b_iodone != NULL); - - cfg = xfs_error_get_cfg(mp, XFS_ERR_METADATA, bp->b_error); + int i; - /* - * If the write was asynchronous then no one will be looking for the - * error. If this is the first failure of this type, clear the error - * state and write the buffer out again. This means we always retry an - * async write failure at least once, but we also need to set the buffer - * up to behave correctly now for repeated failures. - */ - if (!(bp->b_flags & (XBF_STALE | XBF_WRITE_FAIL)) || - bp->b_last_error != bp->b_error) { - bp->b_flags |= (XBF_WRITE | XBF_DONE | XBF_WRITE_FAIL); - bp->b_last_error = bp->b_error; - if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && - !bp->b_first_retry_time) - bp->b_first_retry_time = jiffies; - - xfs_buf_ioerror(bp, 0); - xfs_buf_submit(bp); - return true; + for (i = 0; i < bip->bli_format_count; i++) { + if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map, + bip->bli_formats[i].blf_map_size)) + return true; } - /* - * Repeated failure on an async write. Take action according to the - * error configuration we have been set up to use. - */ - - if (cfg->max_retries != XFS_ERR_RETRY_FOREVER && - ++bp->b_retries > cfg->max_retries) - goto permanent_error; - if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && - time_after(jiffies, cfg->retry_timeout + bp->b_first_retry_time)) - goto permanent_error; - - /* At unmount we may treat errors differently */ - if ((mp->m_flags & XFS_MOUNT_UNMOUNTING) && mp->m_fail_unmount) - goto permanent_error; - - /* still a transient error, higher layers will retry */ - xfs_buf_ioerror(bp, 0); - xfs_buf_relse(bp); - return true; - - /* - * Permanent error - we need to trigger a shutdown if we haven't already - * to indicate that inconsistency will result from this action. - */ -permanent_error: - xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); -out_stale: - xfs_buf_stale(bp); - bp->b_flags |= XBF_DONE; - trace_xfs_buf_error_relse(bp, _RET_IP_); return false; } -/* - * This is the iodone() function for buffers which have had callbacks attached - * to them by xfs_buf_attach_iodone(). We need to iterate the items on the - * callback list, mark the buffer as having no more callbacks and then push the - * buffer through IO completion processing. - */ void -xfs_buf_iodone_callbacks( +xfs_buf_item_done( struct xfs_buf *bp) { /* - * If there is an error, process it. Some errors require us - * to run callbacks after failure processing is done so we - * detect that and take appropriate action. - */ - if (bp->b_error && xfs_buf_iodone_callback_error(bp)) - return; - - /* - * Successful IO or permanent error. Either way, we can clear the - * retry state here in preparation for the next error that may occur. - */ - bp->b_last_error = 0; - bp->b_retries = 0; - bp->b_first_retry_time = 0; - - xfs_buf_do_callbacks(bp); - bp->b_fspriv = NULL; - bp->b_iodone = NULL; - xfs_buf_ioend(bp); -} - -/* - * This is the iodone() function for buffers which have been - * logged. It is called when they are eventually flushed out. - * It should remove the buf item from the AIL, and free the buf item. - * It is called by xfs_buf_iodone_callbacks() above which will take - * care of cleaning up the buffer itself. - */ -void -xfs_buf_iodone( - struct xfs_buf *bp, - struct xfs_log_item *lip) -{ - struct xfs_ail *ailp = lip->li_ailp; - - ASSERT(BUF_ITEM(lip)->bli_buf == bp); - - xfs_buf_rele(bp); - - /* - * If we are forcibly shutting down, this may well be - * off the AIL already. That's because we simulate the - * log-committed callbacks to unpin these buffers. Or we may never - * have put this item on AIL because of the transaction was - * aborted forcibly. xfs_trans_ail_delete() takes care of these. + * If we are forcibly shutting down, this may well be off the AIL + * already. That's because we simulate the log-committed callbacks to + * unpin these buffers. Or we may never have put this item on AIL + * because of the transaction was aborted forcibly. + * xfs_trans_ail_delete() takes care of these. * * Either way, AIL is useless if we're forcing a shutdown. + * + * Note that log recovery writes might have buffer items that are not on + * the AIL even when the file system is not shut down. */ - spin_lock(&ailp->xa_lock); - xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); - xfs_buf_item_free(BUF_ITEM(lip)); + xfs_trans_ail_delete(&bp->b_log_item->bli_item, + (bp->b_flags & _XBF_LOGRECOVERY) ? 0 : + SHUTDOWN_CORRUPT_INCORE); + xfs_buf_item_relse(bp->b_log_item); } |